Aerodynamic impact of total inferior turbinectomy versus inferior turbinoplasty - a computational fluid dynamics study.

BACKGROUND: The aim of this study was to investigate using computational fluid dynamics (CFD) the effects on nasal aerodynamics of two different techniques for reducing the inferior turbinate. This may assist in surgical planning to select the optimal procedure. METHODS: Virtual surgery using two techniques of turbinate reduction was performed in eight nasal airway obstruction patients. Three bilateral nasal airway models for each patient were compared: 1) Pre-operative 2) Bilateral inferior turbinoplasty 3) Bilateral total inferior turbinate resection (ITR). Two representative healthy models were included. CFD modeling of airflow was performed under steady-state, laminar, inspiratory conditions. RESULTS: Nasal airway resistance was slightly more reduced following ITR compared to turbinoplasty due to loss of the pressure gradient at the head of the IT. Turbinoplasty resulted in ventilation, pressure and wall shear stress profiles closer to those of healthy models. A more prominent jet-like course of the main flow stream was observed inferiorly in the ITR group. CONCLUSIONS: Nasal air conditioning was significantly altered following IT surgery. Overall differences between the groups were small and are unlikely to bear influence on nasal function in normal environments. Further studies using a larger number of patients and healthy subjects are required, attempting to establish a clinical correlation with long-term outcomes such as the perception of nasal patency, mucosal crusting and drying, and air conditioning in different environments. Since a large proportion of IT mucosa remains following turbinoplasty, future dependence on topical therapy should also be considered.

Quantification of airflow in the sinuses following functional endoscopic sinus surgery.

BACKGROUND: Despite functional endoscopic sinus surgery (FESS) being the standard of care in medically recalcitrant chronic rhinosinusitis (CRS), its effect on sinus ventilation has not been fully characterized. Airflow simulations can help improve our understanding of how surgical strategies affect post-surgical sinus ventilation. METHODS: Eight postoperative sinonasal cavity models were reconstructed from a wide spectrum of CRS patients who had undergone FESS. Computational fluid dynamics modeling of steady-state, laminar, inspiratory airflow was performed. Ventilation was quantified and observed for all the sinuses in each model. RESULTS: Sinus aeration was enhanced following FESS, particularly in the maxillary and ethmoid sinuses. The degree of improvement was related to the extent of surgery performed. This finding was accentuated at a higher inhalational flow rate of 15L/min. The relationship between ostium size and corresponding sinus inflow was stronger for the maxillary and sphenoid sinuses. Maxillary inflow reached 50% in a mega-antrostomy patient, while negligible flow occurred in the frontal sinuses for except one whom had undergone a modified Lothrop procedure. CONCLUSIONS: This study has quantified sinus airflow in the largest set of post-FESS patients to date, to show that with increasing extensive surgery, the sinus and nasal cavity become more interconnected and functionally interdependent. Accordingly, sinus ventilation is improved. This may have important consequences for pre- and post-surgical assessment and planning, and on predicting how drug delivery treatments and devices can be designed to target the postoperative sinuses.

Measuring antibiotic levels and their relationship with the microbiome in chronic rhinosinusitis.

BACKGROUND: The evidence supporting the efficacy of antibiotic therapy in the treatment of chronic rhinosinusitis is not compelling. A limited number of studies show that the changes in the nasal microbiome in patients following drug therapy are unpredictable and variable. The evidence for the impact of oral antibiotics on the gut microbiota is stronger, possibly as a result of differences in drug distribution to various sites around the body. There are few studies on sinus mucosal and mucus levels of oral antibiotics used in the treatment of chronic rhinosinusitis. The distribution dependent effects of antibiotics on the sinonasal microbiome is unclear. CONCLUSION: This review highlights that relative drug concentrations and their efficacy on microbiota at different sites is an important subject for future studies investigating chronic rhinosinusitis.

Improved gene delivery to adult mouse spinal cord through the use of engineered hybrid adeno-associated viral serotypes.

Adeno-associated viral (AAV) vectors are often used in gene therapy for neurological disorders because of its safety profile and promising results in clinical trials. One challenge to AAV gene therapy is effective transduction of large numbers of the appropriate cell type, which can be overcome by modulating the viral capsid through DNA shuffling. Our previous study demonstrates that Rec2, among a family of novel engineered hybrid capsid serotypes (Rec1~4) transduces adipose tissue with far superior efficiency than naturally occurring AAV serotypes. Here we assessed the transduction of adult spinal cord at two different doses of AAV vectors expressing green fluorescent protein (2 × 109 or 4 × 108 viral particles) via intraparenchymal injection at the thoracic vertebral level T9. In comparison with an equal dose of the currently preferable AAV9 serotype, Rec3 serotype transduced a broader region of the spinal cord up to ~1.5 cm longitudinally and displayed higher transgene expression and increased maximal transduction rates of astrocytes at either dose and neurons at the lower dose. These novel engineered hybrid vectors could provide powerful tools at lower production costs to manipulate gene expression in the spinal cord for mechanistic studies or provide potent vehicles for gene therapy delivery, such as neurotrophins, to the spinal cord.

Circulating cell-free miRNAs as biomarker for triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) accounts for 15-20% of all breast cancer in women globally. This subtype often has early and high recurrence rates resulting in poor survival, partially due to lack of targeted therapies. Therefore, there is an urgent need to identify TNBC-specific biomarkers for early diagnosis and treatment monitoring, and to develop more effective targeted therapy. METHODS: By using miRCURY LNA array platform, we compared the differential miRNA expressions in plasma of patient with TNBC (n=5) and non-TNBC (n=5), as well as healthy controls (n=5). Potential miRNAs were then validated in a large cohort of patients by real-time PCR. RESULTS: Ten putative miRNAs from the microarray data that differentially expressed between non-TNBC and healthy controls were identified. In the screening phase (n=90), we selected five miRNAs (miR-92a-3p, miR-342-3p, miR-16, miR-21 and miR-199a-5p) that could discriminate TNBC from non-TNBC for further validation. Results showed that miR-16, miR-21 and miR-199a-5p were underexpressed in TNBC when compared with non-TNBC, and were further validated in a large cohort (n=252). In addition, post-operative plasma levels of miR-16, miR-21 and miR-199a-5p were significantly restored when compared with pre-operative plasma of TNBC. Plasma miR-199a-5p expression in TNBC had significant difference when compared with non-TNBC and healthy controls, the receiver-operator characteristics curve analysis revealed the highest area under curve (AUC=0.8838) among all. The expression levels were associated with TNM stage and tumour subtypes. CONCLUSIONS: Our data suggest that miR-199a-5p could be a TNBC-specific marker with diagnostic value and provide insights into targeted therapy in the treatment of TNBC.

Omega-3 fatty acids reduce obesity-induced tumor progression independent of GPR120 in a mouse model of postmenopausal breast cancer.

Obesity and inflammation are both risk factors for a variety of cancers, including breast cancer in postmenopausal women. Intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) decreases the risk of breast cancer, and also reduces obesity-associated inflammation and insulin resistance, but whether the two effects are related is currently unknown. We tested this hypothesis in a postmenopausal breast cancer model using ovariectomized, immune-competent female mice orthotopically injected with Py230 mammary tumor cells. Obesity, whether triggered genetically or by high-fat diet (HFD) feeding, increased inflammation in the mammary fat pad and promoted mammary tumorigenesis. The presence of tumor cells in the mammary fat pad further enhanced the local inflammatory milieu. Tumor necrosis factor-alpha (TNF-α) was the most highly upregulated cytokine in the obese mammary fat pad, and we observed that TNF-α dose-dependently stimulated Py230 cell growth in vitro. An ω-3 PUFA-enriched HFD (referred to as fish oil diet, FOD) reduced inflammation in the obese mammary fat pad in the absence of tumor cells and inhibited Py230 tumor growth in vivo. Although some anti-inflammatory effects of ω-3 PUFAs were previously shown to be mediated by the G-protein-coupled receptor 120 (GPR120), the FOD reduced Py230 tumor burden in GPR120-deficient mice to a similar degree as observed in wild-type mice, indicating that the effect of FOD to reduce tumor growth does not require GPR120 in the host mouse. Instead, in vitro studies demonstrated that ω-3 PUFAs act directly on tumor cells to activate c-Jun N-terminal kinase, inhibit proliferation and induce apoptosis. Our results show that obesity promotes mammary tumor progression in this model of postmenopausal breast cancer and that ω-3 PUFAs, independent of GPR120, inhibit mammary tumor progression in obese mice.

Fibulin 1 is downregulated through promoter hypermethylation in gastric cancer.

Tumour suppressor genes (TSGs) were frequently inactivated through promoter hypermethylation in gastric carcinoma as well as pre-malignant gastric lesions, suggesting that promoter hypermethylation can be used as a marker to define novel TSGs and also biomarkers for early detection of gastric cancer. In an effort to search for such genes aberrantly methylated in gastric cancer development, fibulin 1 (FBLN1) was found as a candidate TSG epigenetically downregulated in gastric cancer. FBLN1 expression was downregulated in all of gastric cancer cell lines used (100%, 7 out of 7) and the primary gastric carcinoma tissues (84%, 86 out of 102) and significantly restored after pharmacological demethylation. Hypermethylation of the FBLN1 promoter was frequently (71%, 5 out of 7) detected in gastric cancer cell lines and primary gastric carcinoma tissues. Ectopic expression of FBLN1 led to the growth inhibition of gastric cancer cells through the induction of apoptosis. In summary, FBLN1 was identified as a novel candidate TSG epigenetically downregulated in gastric cancer.

Lymphopenia in dialysis patients: a preliminary study indicating a possible role of apoptosis.

Lymphopenia is a common finding in dialysis patients. Since infection rate and mortality associated with infection are high in dialysis patients, lymphopenia may be one of the contributing factors. In the present study, we evaluated the mechanism responsible for lymphopenia in these patients. Lymphocytes isolated from dialysis patients showed increased apoptosis (p < 0.001) when compared to lymphocytes isolated from healthy subjects (healthy subjects, 0.5 +/- 0.2% vs. dialysis patients, 8.8 +/- 0.7% apoptotic cells/field). Sera from dialysis patients promoted lymphocyte apoptosis in a time- and dose-dependent manner. These sera also enhanced lymphocyte DNA fragmentation into multiple integers of 180 base pairs in the form of a ladder pattern. Cellulose acetate membranes promoted T cell apoptosis when compared to polysulfone membranes and to control. Cellulose acetate dialysis membranes also appear to promote lymphocyte FasL expression. Similarly, dialysis sera enhanced T cell Fas as well as FasL expression. Neither the cellulose acetate nor polysulfone membranes could induce FasL expression on B cells. Similarly, dialysis sera failed to induce FasL expression on B cells. On the other hand, anti-FasL antibodies attenuated dialysis sera-induced apoptosis in T as well as B cells. Interestingly, dialysis serum showed a 5-fold increase in FasL content when compared with control serum. These results suggest that dialysis-associated factors can induce autocrine death in T cells but the help of activated T cells is required to induce death in B cells.

Monocyte apoptosis in dialysis patients is Fas ligand-mediated.

BACKGROUND: The mononuclear phagocyte system plays an important role in host defense. Since dialysis patients have been reported to show enhanced leukocytes apoptosis, we evaluated the mechanism of increased apoptosis of monocytes in dialysis patients. METHODS: Apoptotic studies were carried out on monocytes isolated from dialysis patients as well as healthy subjects. The effect of dialysis sera and membranes was evaluated on monocyte apoptosis as well as monocyte expression of proapoptotic proteins such as Fas and FasL. To confirm the role of FasL, we evaluated the effect of activated secretory products on T cell apoptosis. In addition, we studied FasL content of dialysis sera and supernatants of activated monocytes. RESULTS: Monocytes isolated from dialysis patients (MDP) showed a greater magnitude of apoptosis when compared to monocytes isolated from healthy subjects (MHS) (MHS, 3.6 +/- 1.1% vs. MDP, 24.3 +/-1.4%). Sera of hemodialysis patients (SHD) promoted (p < 0.001) apoptosis of MHS when compared to pooled control sera (HPS) (HPS, 0.8 +/- 0.5% vs. SHD, 11.5 +/- 0.5% apoptotic cells/field). Dialysis membranes, cellulose acetate membranes in particular, promoted monocyte apoptosis. Interestingly, anti-FasL antibodies partly inhibited dialysis sera-induced monocyte apoptosis. Dialysis membranes also modulated monocyte expression of both Fas and FasL. Secretory products of activated monocytes also promoted T cell apoptosis. Dialysis sera and activated monocyte secretory products showed increased FasL content. CONCLUSIONS: These results suggest that dialysis patients have an increased rate of monocyte apoptosis, which is mediated through a uremic milieu (serum factors). One of these serum factors seems to be FasL. In addition, dialysis membranes seem to promote apoptosis independent of the uremic milieu. The present study provides a mechanistical insight into the enhanced apoptosis of monocytes in dialysis patients.

Dialysis membrane-induced neutrophil apoptosis is mediated through free radicals.

Patients on hemodialysis are prone to infection. Neutrophils are the host's first line of defense against certain invading pathogenic microorganisms. Since apoptotic neutrophils are functionally compromised we examined the effect of dialysis membranes on neutrophil apoptosis. Dialysis patients showed greater (p < 0.001) neutrophil apoptosis when compared with control subjects. Cellulose acetate membranes directly promoted (p < 0.001) neutrophil apoptosis. Cellulose acetate membrane-treated neutrophils exhibited greater apoptosis (p < 0.01) when compared with polysulfone membrane-treated neutrophils. Superoxide dismutase (SOD) partly inhibited the cellulose acetate membrane-induced neutrophil apoptosis, whereas both catalase and dimethylthiourea (DMTU) inhibited the polysulfone membrane-induced neutrophil apoptosis. Similarly, L-NAME, a nitric oxide synthase inhibitor, attenuated both the cellulose acetate and the polysulfone membrane-induced neutrophil apoptosis. In addition, cellulose acetate and monocyte interaction products promoted (p < 0.001) neutrophil apoptosis. These results suggest that dialysis membranes can promote neutrophil apoptosis directly as well as through their interaction with monocytes. The direct effect of dialysis membranes seems to be mediated partly through the generation of reactive oxygen species.

Insulin-like growth factor binding protein-1 induces insulin release in the rat.

Injections of human insulin-like growth factor binding protein (hIGFBP-1) are reported to induce hyperglycemia in the rat, suggesting that IGFBP-1 acutely regulates glucose homeostasis. We now report the effects on glucose and insulin levels of administering recombinant (r) hIGFBP-1. In a series of studies, normal and streptozotocin (STZ) diabetic male Wistar rats (180-210 g), fasted for 6 or 16 h, were injected with rhIGFBP-1 (i.v., 80-500 microg/rat). rhIGFBP-1 did not affect blood glucose acutely but did stimulate insulin release in normal rats (5 min post injection; PBS, 103.5 +/- 8.5; rhIGFBP-1 (500 microg), 166.8 +/- 15.7; rhIGFBP-1 (100 microg); 151.4 +/- 14.1% initial). rhIGFBP-1 pretreatment, in normal and diabetic rats, reduced the hypoglycemic response to rhIGF-I (diabetic rats after 20 min: PBS, 103.4 +/- 11.4; BP-1 (500 microg) +/- rhIGF-I (50 microg), 97.6 +/- 3.6; rhIGF-I, 48.2 +/- 4.3% initial) but did not affect the hypoglycemic response to des(1-3)IGF-I or insulin (0.5 U/kg). These studies show that rhIGFBP-1 causes insulin release, has a minimal effect on blood glucose, and inhibits the hypoglycemic effect of rhIGF-I. These data suggest that endogenous IGF-I tonically suppresses insulin secretion and imply that aberrant IGFBP levels or reduced IGF-I bioactivity may lead to chronic hyperinsulinemia.

Dietary Juniperis virginiensis seed oil decreased pentobarbital-associated mortalities among DBA/1 mice treated with collagen-adjuvant emulsions.

The propensity of the fatty acid 5,11,14-eicosatrienoic acid (5,11,14-ETA) to replace arachidonic acid in cell membranes, and its inability to be converted to bioactive eicosanoids, suggest that it may be useful in the treatment of autoimmune disorders. Previously, dietary application of oils extracted from 5,11,14-ETA-rich Platycladus orientalis delayed the onset of autoimmune disease in New Zealand Black mice. To gain more knowledge of the efficacy of this fatty acid toward alleviating immunological disorders, a similar oil was used to examine its effects on collagen-induced arthritis in DBA/1 mice, a model characterized by synovial proliferation and joint infiltration by inflammatory cells. Mice were fed AIN76A diet supplemented with 4% (w/w) of either an oil extracted from the seeds of Juniperis virginiensis (0.4% 5,11,14-ETA); a control oil consisting of equal parts olive, linseed and safflower oils; fish oil (90% fish oil and 10% safflower oil); or safflower oil. Mice were immunized with three injections of collagen-adjuvant emulsions, the first injection was intradermal, and the two subsequent injections were intraperitoneal. Mortalities were recorded following a secondary pentobarbital administration intraperitoneally. Mice from the J. virginiensis group had the lowest mortalities (25%) while safflower oil-fed mice had the highest (59%; p < 0.05). While the J. virginiensis group had the lowest mean CD4/CD8 T lymphocyte ratio, the fish oil group had the highest. These observations suggest that manipulation of eicosanoid production by different dietary lipids had different effects on immune responses, possibly through alterations in T lymphocyte subsets. Hypothetically, a downregulation of prostaglandin E2 release could increase the ratio of T helper 1 to T helper 2 lymphocytes and thereby modulate anaphylactic responses. Also, lowered pro-oxidant status may decrease CD4/CD8 T cell ratios and modify immune function.

Molecular genetics of anti-carbohydrate antibodies.

Antibodies directed against carbohydrate determinants provide useful model systems for understanding the structure and organisation of antibody genes and the generation of antibody diversity. We have used three such systems, PC, DEX and GAC, and have studied the heavy chains and VH gene segments of each. In two of these systems, PC and GAC, much of the diversity in heavy-chain protein sequences results from somatic mutation events superimposed on expression of a single VH gene. In the DEX system, it appears that germ-line sequence diversity may be an important contributor to the variability in heavy-chain sequence. Detailed structural analyses of this type will ultimately provide a complete picture of the mechanisms which underlie effective humoral immunity.

The affinity of catechol estrogens for estrogen receptors in the pituitary and anterior hypothalamus of the rat.

The purpose of these experiments was to evaluate the potential for interaction between 2-hydroxyestrone and 2-hydroxyestradiol and estrogen receptors in rat pituitary and anterior hypothalamus. The 150,000 X g supernatant fractions of these tissues were prepared, the estrogen receptor-site concentration was measured, and the relative abilities of unlabelled estradiol, estrone, 2-hydroxyestradiol and 2-hydroxyestrone to compete with [3H]estradiol for estrogen binding sites was determined. From these results, and the previously determined association constant for [3H]estradiol, 10(10)M-1, the association constants of the other estrogens were calculated. The introduction of the 2-hydroxy group caused only a modest reduction in the affinity of these estrogens for the receptors. The association constants of the 2-hydroxy derivatives were within one order of magnitude of those of the parent compounds. These results demonstrate the potential for interaction between catechol estrogens and estrogen receptor in rat brain and pituitary of a magnitude which could be biologically significant.

A specific, high-affinity, limited-capacity estrogen binding component in the cytosol of human fetal pituitary and brain tissues.

A macromoleclar component which binds 3H-estradiol with high affinity and limited capacity is present in the 150,000 x g supernatant fraction of pituitary, hypothalamus, cortex, and limbic system of both male and female human fetwses. 17 beta-estradiol and 17alpha-ethinylestradiol effectively compete with 3H-estradiol for binding sites while testosterone, dihydrotes-tosterone, and cortisol do not. The binding component is different from sexhormone-binding-globulin. It is present in these tissues in relatively large amounts and it is tentatively identified as an estrogen recptor.

Estradiol receptors in the pituitary and anterior hypothalamus of the rat: measurement by agar gel electrophoresis.

PIP: The reliability of agar gel electrophoresis in the measurement of high-affinity saturable estrogen-binding component in the cytosol of the rat pituitary gland and anterior hypothalamus was assessed. The available binding sites were determined in small samples with good precision and accuracy. Incubation with 100-fold competitor was more satisfactory than heat-treatment for measuring nonspecific binding. There was substantial, but incomplete, dissociation of albumin-estradiol complexes. The total number of estrogen binding sites in the anterior hypothalamus was approximately 15% greater in 28-day-old females than males (p .02). However, differences in the number of binding sites in the pituitary was not significant (p .02). The pituitary was found to contain twice as many binding sites as the anterior hypothalamus in both sexes. The latter finding is consistent with the importance of the direct action of estrogen on the pituitary in mediating pituitary function.^ieng